Kinnickinnic River Watershed

The Kinnickinnic River Watershed covers an area of 33.4 square miles located entirely within Milwaukee County. The Watershed contains 25 miles of perennial streams including Wilson Park Creek and its tributaries. The Kinnickinnic River is the smallest of the watersheds within the Milwaukee River Basin, but it is also the most developed, with approximately 40% of its area covered in impervious surfaces (SEWRPC 2009). Land cover in the Kinnickinnic River Watershed is about 97% urban, 2% grassland/forested, 0.39% wetlands, and approximately 0.77% allocated between seven park ponds (WDNR 2016).

Historically, to facilitate extensive development and reduce flooding within the Kinnickinnic River Watershed, the river was channelized with concrete and leveed to quickly move water downstream. As a result, water levels rise rapidly during precipitation events in these streams, and then quickly return to low flow as water flushes through their channels on its way to Lake Michigan (Figure 8). Sections of stream that are channelized with concrete and straightened provide minimal habitat for aquatic organisms, and sections that are not channelized experience high levels of erosion because of the huge volumes of water coming from concrete channels upstream. Around 60% of the streams within the Kinnickinnic River Watershed are lined with concrete or held within a modified enclosed channel (WDNR 2011).

Furthermore, around 85% of the land use within 100 feet of streams in the Kinnickinnic River Watershed is categorized as urban/developed (WDNR 2016). The WDNR recommends at least a 75-100 foot natural buffer adjacent to Wisconsin streams to protect water quality. Riparian buffers help create habitat for aquatic species, minimize the levels of contaminants that enter our streams during precipitation events, and generally improve the resilience of stream ecosystems (WDNR 2013). Many Kinnickinnic River ecosystems are also impeded by a series of culverts, conduits, and drop structures that fragment the stream and limit habitat connectivity. Physical barriers within and along the stream (e.g., seawalls and stone) can reduce the diversity and connectivity of existing habitat, by making it difficult for aquatic organisms to move up and downstream, or between instream and riparian habitat, while also causing significant impacts to water quality.